Cycling heat dissipation module

ABSTRACT

A cycling heat dissipation module suited for dissipating heat generated from a heat source is provided. The cycling heat dissipation module includes an evaporator, a condenser, and a micro/nano-structure. The evaporator is thermal contacted with the heat source to absorb heat generated therefrom. The condenser is connected to the evaporator to form a loop, and a working fluid is filled in the loop. The working fluid in liquid state is transformed to vapor state by absorbing heat in the evaporator, and the working fluid in vapor state is transformed to liquid state by dissipating heat in the condenser. The micro/nano-structure is disposed in the condenser to destroy a boundary layer of the working fluid while passing through the condenser.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the priority benefit of Taiwan applicationserial no. 107107762, filed on Mar. 7, 2018. The entirety of theabove-mentioned patent application is hereby incorporated by referenceherein and made a part of this specification.

BACKGROUND OF THE DISCLOSURE Field of the Disclosure

The disclosure is related to a heat dissipation module, and particularlyto a cycling heat dissipation module.

Description of Related Art

A heat-dissipating technology with two phases is developed by usinglatent heat conversion with transition of vapor-liquid phases todissipate heat from electronic element. The basic principle of thetechnology uses the process that cooled liquid is evaporated into vaporwhen being heated through thermal contact with heat source in anevaporator, thereby dissipating a large amount of heat generated fromthe heat source. A force is generated by the vapor being formedcontinuously, such hat the vapor flows away from the evaporator. Afterbeing dissipated and cooled gradually, the vapor is condensed intoliquid and returns back to the evaporator for the next heat-absorbingprocess.

In this manner, a cycle is formed with heat exchange (working fluidabsorbs heat) in evaporator and heat exchange (working fluid dissipatesheat) leaving evaporator, such that the working fluid can move smoothlybetween the planned evaporator and piping.

However, experiments of visualization of fluid show that, after beingtransformed into vapor and leaves the evaporator, the working fluidgenerates a slug flow phenomenon in the piping which causes a boundarylayer formed on a wall of the piping. Therefore, heat exchange betweenthe vapor and the tube wall is ineffective because of the boundary layerblocking between the vapor and the tube wall; as a result, theheat-dissipation efficiency of the cycle is reduced.

SUMMARY OF THE DISCLOSURE

The disclosure provides a cycling heat dissipation module, which uses amicro/nano structure to destroy a boundary layer generated by workingfluid when travelling through condensing segment, thereby improving theheat exchange efficiency of working fluid at the condensing segment.

In the disclosure, the cycling heat dissipation module is configured todissipate heat generated from heat source. The cycling heat dissipationmodule includes an evaporator, a condenser and a micro/nano-structure.The evaporator is thermal contacted with heat source to absorb the heatgenerated by the heat source. The condenser is connected to theevaporator to form a loop. The working fluid is filled in the loop. Theworking fluid in liquid state is transformed to vapor state by absorbingheat in the evaporator, and the working fluid in vapor state istransformed to liquid state by dissipating heat in the condenser. Themicro/nano-structure is disposed on the condenser to destroy a boundarylayer of the working fluid when travelling through the condenser.

In the disclosure, the cycling heat dissipation module is configured todissipate heat generated from heat source. The cycling heat dissipationmodule includes an evaporator and a piping. The evaporator has a firstoutlet and a first inlet. The piping is connected to the first outletand the first inlet of the evaporator to form a loop. The working fluidis filled in the loop. The working fluid in liquid state is transformedinto vapor state by absorbing heat in the evaporator and flows out ofthe evaporator through the first outlet. The piping has a heat-blockingsegment and a condensing segment, wherein the heat-blocking segment isdisposed between the first outlet and the condensing segment, and theworking fluid in vapor state is transformed into liquid state bydissipating heat at the condensing segment and flows into of theevaporator through the first inlet.

According to the above, by disposing the micro/nano-structure at thecondensing segment, the cycling heat dissipation module is able todestroy the boundary layer formed by the working fluid in liquid-phaseon the tube wall at the condensing segment when the working fluid passesthrough the condensing segment in the form of a mixed phase of liquidand vapor. In this manner, the working fluid in vapor-phase candissipate heat smoothly through the tube wall, thereby achieving abetter heat exchange efficiency. Furthermore, when the working fluid inliquid-phase is transformed into vapor-phase by absorbing heat in theevaporator and flows out of the evaporator to move toward the condensingsegment, with the heat-blocking segment that is disposed between theoutlet of the evaporator and the condensing segment in the piping, notonly that it is possible to prevent the heat absorbed by the workingfluid from affecting other surrounding elements in the area, but also atraveling force of the working fluid in vapor-phase can be maintainedeffectively, thereby ensuring that the working fluid can move smoothlyin the loop through cycle.

In order to make the aforementioned features and advantages of thedisclosure more comprehensible, embodiments accompanying figures aredescribed in detail below.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view of a cycling heat dissipation moduleaccording to an embodiment of the disclosure.

FIG. 2 shows working fluid in vapor-phase/liquid-phase status whentravelling through condensing segment.

FIG. 3A is schematic view of a portion of a tube in FIG. 1.

FIG. 3B is a schematic view showing fabrication of the portion of thetube in FIG. 3A.

FIG. 4A is a schematic view of a cycling heat dissipation moduleaccording to another embodiment of the disclosure.

FIG. 4B is a schematic view of a portion of a cycling heat dissipationmodule according to yet another embodiment of the disclosure.

FIG. 5A is a schematic view of a cycling heat dissipation moduleaccording to still another embodiment of the disclosure.

FIG. 5B and FIG. 5C are schematic views showing a portion of a cyclingheat dissipation module according to different embodiments.

DESCRIPTION OF EMBODIMENTS

FIG. 1 is a schematic view of a cycling heat dissipation moduleaccording to an embodiment of the disclosure. FIG. 2 shows working fluidin vapor-phase/liquid-phase status when travelling through condensingsegment. Referring to FIG. 1 and FIG. 2, in the embodiment, a cyclingheat dissipation module 100 is configured to dissipate heat generatedfrom a heat source 200, and the cycling heat dissipation module 100includes an evaporator 110, a working fluid F1 and a condenser. Thecondenser includes a tube 120 and a heat-dissipating board 130 that abutupon each other in structure, wherein the tube 120 is connected to theevaporator 110 to form a loop such that the working fluid F1 is filledin the loop. With the configuration that the working fluid F1 istransformed between liquid-phase/vapor-phase by absorbing/dissipatingheat, the effect of dissipating heat generated by the heat source can beachieved.

For example, in the interior of portable electronic device such asnotebook computer or smart phone, due to increase of performance, it isinevitable that dissipating heat generated from electronic elementbecomes an issue to be solved. In this regard, according to theembodiment, the evaporator 110 and the heat source 200 (e.g., processoror display chip of electronic device) are thermal contacted with eachother, and for example, through the configuration of heat pipe, the heatgenerated by the heat source 200 is transferred to the evaporator.Certainly, it is possible to directly abut the structure of theevaporator 110 upon the heat source 200 to directly absorb the heatgenerated therefrom. The disclosure provides no limitation to how theevaporator and the heat source are thermal contacted with each other.

In this manner, when travelling through the evaporator 110, the workingfluid F1 in liquid-phase is able to be transformed into vapor-phase byabsorbing heat, and moves toward the condenser from the evaporator 110.As described above, since the tube 120 and the heat-dissipating board130 abut upon each other in structure, when the working fluid F1 invapor-state travels through the tube 120, the working fluid F1 invapor-state is gradually transformed into liquid-state because the heatis absorbed by the heat-dissipating board 130, and then returns to theevaporator 110 again along the tube 120 to complete a cycle. In theembodiment, only the heat-dissipating board 130 is exemplified as astructure for dissipating the heat of the working fluid F1, which shouldnot be construed as a limitation to the disclosure. In other embodimentsthat are not shown, the heat-dissipating board 130 may be replaced byother existing related elements capable of achieving heat-dissipationeffect such as a heat-dissipating fin, a housing of an electronic devicecapable of conducting heat, a fan and so on.

As shown in FIG. 2, along with the working fluid F1 that travels throughthe tube 120 and dissipates heat, there is working fluid F1 invapor-phase (as bubble G1 shown in FIG. 2) and working fluid F1 inliquid-phase in the tube 120, and thus a slug flow is generated as thebubble G1 shown in FIG. 2. As a result, boundary layers M1 and M2 areformed between the working fluid F1 in liquid-phase and the wall of tube120. The presence of the boundary layers M1 and M2 blocks the workingfluid (bubble G1) in vapor-state from the tube wall, and causes the heatof the working fluid F1 in vapor-state unable to be continuouslydissipated through the tube wall.

Accordingly, the embodiment further forms a micro/nano-structure on thewall of the tube 120 so as to destroy the boundary layers M1 and M2described above, such that the working fluid F1 in vapor-phase is ableto be in contact with the tube wall smoothly without being blocked,thereby achieving the heat-dissipation effect.

Specifically, FIG. 3A is schematic view of a portion of the tube inFIG. 1. FIG. 3B is a schematic view showing fabrication of the portionof the tube in FIG. 3A. Referring to FIG. 3A and FIG. 3B and comparingthem with FIG. 1, in the embodiment, a rough layer element 140 iscombined with an inner wall of the tube 120 to complete themicro/nano-structure. As shown in FIG. 3B, the completed rough layerelement 140 is inserted into the tube 120 through fixtures J1 and J2which are driven relatively and positioned to the required position.Next, the tube 120 is partially deformed corresponding to two oppositeends of the rough layer element 140, such that the rough layer element140 can be fixed within the tube 120 when the tube diameter is reduced.In this manner, the fixtures J1 and J2 can be removed smoothly and thecombination of the rough layer element 140 and the tube 120 iscompleted. However, the disclosure provides no limitation to theabove-mentioned means for combination. In another embodiment that is notshown, the micro/nano-structure may be, for example, formed integrallyon a rough structure of the inner wall of the tube 120 through sinteringprocess. It should be indicated that the disclosure provides nolimitation to the range of the micro/nano-structure in the tube 120, themicro/nano-structure may be a portion of or the entire tube 120 shown inFIG. 1.

With such configuration, when the working fluid F1 travels through wherethe micro/nano-structure is present in the tube 120, the boundary layergenerated by the working fluid F1 on the tube wall can be destroyed withsuch structure, such that the working fluid F1 in vapor-phase candissipate heat through the tube wall. In the meantime, with suchconfiguration, the heat exchange efficiency of working fluid F1 can beenhanced, and the travelling force required for the working fluid F1 totravel in the loop can be provided sufficiently.

FIG. 4A is a schematic view of a cycling heat dissipation moduleaccording to another embodiment of the disclosure. Referring to FIG. 4A,in the embodiment, the cycling heat dissipation module includes theevaporator 110 and a piping 320, wherein the evaporator 110 is the sameas described in the previous embodiment, and the piping 320 is furtherclassified into a heat-blocking segment L1 and a condensing segment L2,wherein the heat-blocking segment L1 is connected between an outlet E1of the evaporator 110 and the condensing segment L2, and the condensingsegment L2 is connected between the heat-blocking segment L1 and aninlet E2 of the evaporator 110. Furthermore, the cycling heatdissipation module further includes a heat-blocking material 310covering the heat-blocking segment L1. In this manner, with the presenceof the heat-blocking material 310 at the heat-blocking segment L1, whenthe working fluid F1 that is transformed into vapor-state and flows fromthe evaporator 110 to the heat-blocking segment L1 of the piping 320, itcan be avoided that the working fluid F1 dissipates heat through beingin contact with a heat-blocking board 330 or other elements capable ofdissipating heat, and thus the working fluid F1 can still maintain to bein vapor-state. Meanwhile, the travelling force of the working fluid F1can be maintained accordingly, thereby avoiding loss of the travelingforce of the working fluid F1 due to premature heat exchange.Additionally, such configuration also makes it possible to avoid that,when the elements in the electronic device are arranged closely (in acompacted manner), the heat of the working fluid F1 is likely to affectother elements at the heat-blocking segment L1, and results in loss ofthe heat from the working fluid F1, and it is also possible to avoidaffecting the operation performance of other elements. Subsequently,when the working fluid F1 travels through the condensing segment L2, theheat-dissipating board 330 is used to perform the above-mentionedheat-dissipating operation.

FIG. 4B is a schematic view of a portion of a cycling heat dissipationmodule according to yet another embodiment of the disclosure. It shouldbe descried that the cycling heat dissipation module in the embodimentstill has the connection relationship as shown in FIG. 4A. Thedifference between the embodiment and the previous embodiment is that aheat-blocking segment L3 is supported at a higher position as comparedwith a condensing segment L4 or the evaporator 110. Specifically, theembodiment uses a supporting structure 410 to support the heat-blockingsegment L3 on a base B1 of the electronic device, thereby avoiding thatthe surrounding elements are affected by heat as described above. Also,it is possible to prevent the working fluid F1 from losing excessiveheat when travelling through the heat-blocking segment L3 and thuslosing travelling force for travelling through a piping 420 in thesubsequent process.

FIG. 5A is a schematic view of a cycling heat dissipation moduleaccording to still another embodiment of the disclosure. Referring toFIG. 5A, in a cycling heat dissipation module 500 of the embodiment, thecondenser includes a tube 520, a tank 530 and a micro/nano-structuredisposed in the tank 530. As shown in FIG. 5A, the tube 520 is connectedto the inlet E2 and the outlet E1 of the evaporator 110 as well as aninlet E3 and an outlet E4 of the tank 530. That is, the tank 530 may beregarded as a condensing segment disposed at the piping, or the tank 530may be regarded as a condensing segment of the cycling heat dissipationmodule 500. Herein, the micro/nano-structure is a plurality ofprotrusions disposed in the tank 530 and arranged in arrays, such thatthe boundary layer between the working fluid F1 and the inner wall ofthe tank 530 can be destroyed due to the protrusions when the workingfluid F1 flows into the tank 530. In this manner, the working fluid F1in vapor-state is able to perform heat exchange (dissipate heat) in thetank 530 smoothly and transformed into liquid-state, and then flows intothe evaporator 110 through the tube 520 and the inlet E2.

However, the disclosure provides no limitation to the shape of themicro/nano-structure in the tank. FIG. 5B and FIG. 5C are schematicviews showing a portion of a cycling heat dissipation module accordingto different embodiments, and provided to show a different type of tankas compared with the tank 530 shown in FIG. 5A. In a tank 530A shown inFIG. 5B, a plurality of groove structures are disposed therein, whereasin a tank 530B shown in FIG. 5C, a plurality of fin structures arrangedin specific direction are disposed therein. No matter what shape of themicro/nano-structure is, the micro/nano-structure is capable ofachieving the effect of destroying the boundary layer generated by theworking flow F1 when travelling through the tank. In other words, themicro/nano-structure in the disclosure may include at least one of aprotrusion, a groove, a fin or an etching structure, thereby destroyingthe boundary layer between the working fluid and the inner wall of thepiping such that the working fluid in vapor-phase is able to dissipateheat smoothly. In the other way around, a position in the piping of thecycling heat dissipation module where the micro/nano-structure isdisposed may be regarded as a condenser or a condensing segment thattransforms the working fluid F1 in vapor-phase into the working fluid F1in liquid-phase.

In summary of the above, according to the embodiments of the disclosure,the cycling heat dissipation module disposes the micro/nano-structure atthe condensing segment to destroy the boundary layer that is formed bythe working fluid in liquid-phase on the tube wall at the condensingsegment when the working fluid travels through the condensing segment inthe mixed phase of liquid and vapor. In this manner, the working fluidin vapor-phase is able to dissipate heat smoothly through the tube wall,thereby achieving a better heat exchange efficiency. Furthermore, whenthe working fluid in liquid-phase is transformed into vapor-phase byabsorbing heat in the evaporator, and moves toward the condensingsegment after being transferred out of the evaporator, by disposing theheat-blocking segment between the outlet of the evaporator and thecondensing segment in the piping, not only that it is possible toprevent the heat absorbed by the working fluid from affecting othersurrounding elements in the area, but also the traveling force of theworking fluid in vapor-phase can be maintained effectively, therebyensuring that the working fluid can move smoothly in the loop throughcycle.

Moreover, the micro/nano-structure may be a rough structure or a roughlayer element in the inner wall of tube, and a tank may be disposed on aportion of the piping, and at least one of the protrusion, groove, finor etching structure may be formed in the tank, such that the pipingwith uneven surface can achieve the purpose of destroying the boundarylayer of the working fluid.

Although the disclosure has been disclosed by the above embodiments, theembodiments are not intended to limit the disclosure. It will beapparent to those skilled in the art that various modifications andvariations can be made to the structure of the disclosure withoutdeparting from the scope or spirit of the disclosure. Therefore, theprotecting range of the disclosure falls in the appended claims.

What is claimed is:
 1. A cycling heat dissipation module, configured todissipate heat generated from a heat source, the cycling heatdissipation module comprising: an evaporator, thermal contacted with theheat source to absorb heat generated by the heat source; a condenser,connected to the evaporator to form a loop, a working fluid filled inthe loop, wherein the working fluid in liquid-state is transformed intovapor-state by absorbing heat in the evaporator, and the working fluidin vapor-state is transformed into liquid-state by dissipating heat inthe condenser; and a micro/nano-structure, disposed on an inner wall inthe condenser to destroy a boundary layer formed by the working fluidwhen travelling through the condenser.
 2. The cycling heat dissipationmodule according to claim 1, wherein the working fluid generates a slugflow in the condenser due to presence of vapor and liquid phases, andthe boundary layer is formed between the working fluid and thecondenser.
 3. The cycling heat dissipation module according to claim 1,wherein the condenser comprises a tube connected to the evaporator toform the loop, and the micro/nano-structure is a rough structure formedon the inner wall of the tube.
 4. The cycling heat dissipation moduleaccording to claim 1, wherein the condenser comprises a tube connectedto the evaporator to form the loop, and the micro/nano-structure is arough layer element combined with the inner wall of the tube.
 5. Thecycling heat dissipation module according to claim 1, furthercomprising: a tube, connected to the evaporator to form the loop,wherein the condenser comprises a tank connected between a portion ofthe tube, and the micro/nano-structure is disposed in the tank.
 6. Thecycling heat dissipation module according to claim 5, wherein themicro/nano-structure is at least one of a protrusion, a groove, a fin oran etching structure disposed in the tank.
 7. The cycling heatdissipation module according to claim 1, further comprising: aheat-blocking segment, connected between the condenser and theevaporator; and a heat-blocking material, covering the heat-blockingsegment.
 8. The cycling heat dissipation module according to claim 7,wherein the heat-blocking segment is supported at a higher positionrelative to the condenser or the evaporator.